Conventionally, a feed-through configured as shown in FIG. 4 is used as a feed-through for feeding electric power to a submerged pump installed in a tank for cryogenic liquefied gas, such as LNG and LPG (refer to, for example, Patent Literatures 1 to 4). In a feed-through 10 in FIG. 4, a ceramic bushing 16 (only two bushings are shown in FIG. 4) is inserted into each of three bushing insertion holes 14 on a stainless steel, disc-shaped flange (partitioning flange) 12. A conductor 18 is inserted into a hollow portion of the bushing 16. Gaps between the flange 12 and each end of the bushing insertion holes 14 are hermetically sealed by sealing sections that are sealing members 24 and 26, such as bellows. Gaps between both ends of the bushings 16 and the conductor 18 are sealed by sealing sections that are sealing members 24 and 26, such as bellows.
The feed-through 10 of the example is fixed onto an LNG tank by, for example, the flange 12 being layered onto an upper end flange section of a pump housing pipe projecting outwards from an upper wall of the LNG tank, and hermetically fixed. In this state, in the feed-through 10, a low temperature side terminal 28 is inserted into the pump housing pipe, and a low temperature cable is connected to the low temperature side terminal 28. An ordinary cable is connected to an external air side terminal 30 that is outside. As a result, electric power can be fed to the submerged pump housed within the pump housing pipe of the LNG tank, via the cable, the feed-through 10, and the low temperature cable.    Patent Literature 1: Japanese Patent Laid-open Publication No. Heisei 8-338596    Patent Literature 2: Japanese Patent Laid-open Publication No. Heisei 10-116529    Patent Literature 3: Japanese Patent Laid-open Publication No. Heisei 10-116530    Patent Literature 4: Japanese Patent Laid-open Publication No. 2002-340295